We are bulls

There was a farmer who had a lot of live stock. He had cows, horses, chickens, pigs, and bulls. One day a terrible twister came and the man and his family were only saved by throwing themselves in the nearest ditch. After it was all over, he looked up to see that the house was gone. Saddened by the loss, he went out to see if any of the animals had survived. The horses, chickens, pigs, and cows were laid out flat but the bulls were standing! The farmer was amazed and asked them, "How is it that all the other animals are down and you are still standing?" The bulls replied, "We bulls wobble but we don't fall down!"